1. Technical Field
The present disclosure generally relates to phlebotomy needle assemblies and, in particular, relates to needle assemblies including extensions for visualizing “flashback”.
2. Background of Related Art
Venipuncture is the primary method used for acquiring blood samples for laboratory testing. Various venipuncture devices have been developed to aid a phlebotomist in acquiring blood samples. Typically, a venipuncture device includes a needle holder having a needle that is inserted into a vein. When a vacuum tube is inserted into the needle holder, the vacuum tube begins to fill with blood confirming that the vein has been entered. During a single blood collection procedure, one or more vacuum tubes may be filled in this manner. Attempts have been made to develop improved venipuncture devices that include a “flashback” mechanism incorporated into the needle holder. These “flashback” mechanisms typically include venting structure which allows a sufficient amount of blood to enter the venipuncture device to reach a flashback chamber and, thus, allow a phlebotomist to visually confirm that a vein has been entered. However, the various venting means and/or chamber configurations permitting visualization of the “flashback” may be complicated, and therefore, expensive to manufacture. Further, in phlebotomy needle assemblies which do not have venting structure, a vacuum tube must be inserted into the needle holder before blood will flow through the needle assembly and flashback can be observed.